1. Field of the Invention
The present invention relates to an armrest locking device, and more particularly, to an armrest locking device having no risk of unintentional unlocking upon a car crash.
2. Description of the Related Art
In accordance with a regulation of Korean safety standards related to interior compartment doors of automobiles, a locking device for an automobile interior receiving structure, for example, an armrest locking device, has to be designed so as not to be opened upon a car crash.
To fulfill the above regulation, there has been suggested in the prior art that a button spring as one component of the locking device has a high strength sufficient to overcome an inertia moment produced by weights of a push button and a hook. However, using the high-strength button spring makes for a user to press the push button with a great force even in a normal use situation and therefore, may result in a degradation in the convenience of passengers and the merchantability of automobiles.
FIG. 1 is a sectional view illustrating the configuration of a conventional armrest locking device, and FIG. 2 is a sectional view illustrating a state in which a push button of the conventional armrest locking device is retracted by a rear crash shock.
As shown, the conventional armrest locking device includes an armrest body 10 defining a receiving space therein, an armrest cover 20 for opening and closing the armrest body 10, a push button 30 for regulating locking and unlocking of the armrest cover 20, a hook member 35 configured to move along with the push button 30, and an elastic member 32 for supporting the push button 30.
The armrest cover 20 is coupled to the armrest body 10 by use of a hinge 22, to have a pivotally rotatable structure. The push button 30 is disposed at a front surface of the armrest cover 20 such that the push button 30 is retractable by manual operation of a user. The push button 30 is able to be returned to an original position thereof by a restoration force of the elastic member 32.
If the push button 30 is pressed, the hook member 35 is pushed rearward of the armrest body 10 as the elastic member 32 is constricted, resulting in unlocking of the armrest locking device.
With this configuration, it will be appreciated that the higher the strength of the elastic member 32, a greater force should be applied to press the push button 30, whereas the lower the strength of the elastic member 32, the push button 30 is able to be easily pressed even by a smaller force.
Meanwhile, interior compartment doors of an automobile have a regulation in that the doors should not be opened upon a car crash.
In particular, a rear car crash is problematic. As shown in FIG. 2, if an automobile has a rear crash, the push button 30 is pushed rearward by an inertia force. However, if the push button 30 is pushed rearward beyond a predetermined distance upon receiving a crash shock, the armrest locking device may experience an unintentional unlocking and therefore, have a difficulty to fulfill the above described safety regulation.
Accordingly, there has been conventionally suggested to provide the elastic member 32 with a high strength, so as to prevent the push button 30 from being unintentionally pushed rearward. However, the elastic member 32 having the high strength makes for a user to apply a great force to the push button 30 for opening of an armrest and this is undesirable in the viewpoints of the operating performance of the armrest locking device and the convenience of use.